Problem with class

[etrusks]

So here is all files..

//polygon.h
#ifndef POLYGON_H
#define POLYGON_H
class polygon{
 
 protected:
    float x,y;
 public: polygon();
        ~polygon();
        void setData(float,float);
};
#endif 

//triangle.h
#ifndef TRIANGLE_H
#define TRIANGLE_H

class triangle{
          
public:  triangle();
         ~triangle();  
         float areaTR();
};
#endif 

//rectangle.h
#ifndef RECTANGLE_H
#define RECTANGLE_H

class rectangle{
    public:      
    rectangle();
    ~rectangle();    
     float areaRE();	 
};
#endif 

//polygon.cpp
#include "polygon.h"

void polygon::setData(float a,float b)
{
a=x;b=y;
}

//triangle.cpp
#include "triangle.h"

public: polygon{     
float triangle::areaTR(){return x*y/2;}
} 

//rectangle.cpp
#include "rectangle.h"

public: polygon{
    float rectangle::areaRE(){return x*y;}
}

//500.cpp
#include<iostream>
#include "polygon.h"
#include "triangle.h"
#include "rectangle.h"
using namespace std;
 main(){
 
 triangle tr;
 rectangle re;
 tr.setData(2.,5.);
 re.setData(2.,5.);
 cout<<tr.areaTR()<<endl;
 cout<<re.areaRE()<<endl;
 return 0;
 }
 

When i try to compile ir writing g++ 500.cpp polygon.cpp triangle.cpp rectangle.cpp -o 500 it shows these errors:

g++ 500.cpp polygon.cpp rectangle.cpp triangle.cpp -o 500

500.cpp: In function ‘int main()’:
500.cpp:11: error: ‘class triangle’ has no member named ‘setData’
500.cpp:12: error: ‘class rectangle’ has no member named ‘setData’
rectangle.cpp:4: error: expected unqualified-id before ‘public’
triangle.cpp:4: error: expected unqualified-id before ‘public’

Can anyone tell me what can i do to make it work? Exercise of this program
is to get triangle and rectangle areas.

[eker676]

Include the .cpp files not the .h files.

[Disch]

Generally you don't include cpp files.

You're deriving your classes wrong. If you want rectangle to be derived from polygon you do it like so:

class rectangle : public polygon
{
 // rectangle stuff here
};

This also means you'll have to #include "polygon.h" before "rectangle.h" in any file that uses it

Also I'm not sure where you got the syntax for your member function bodies in rectangle/triangle.cpp, but it should be like this:

// rectangle.cpp
#include "polygon.h"
#include "rectangle.h"

float rectangle::areaRE()
{
  return x*y;
}

Strange that you did this properly for polygon::setData

[etrusks]

Tnx you guys now its working, i dont know what would i do without you :)